MnO4 in this compound is a polyatomic ion. MnO4-1 refers to the ion- permanganate.
CO3(2-) Carbonate.
The polyatomic ion in KNO3 (potassium nitrate) is NO3- , the nitrate ion. This ion is polyatomic because it contains four atoms bonded together. The nitrate ion is derived from nitric acid, HNO3.
They are both ions and both can form an ionic compound
it is sulfate, sulfite and many more.... Common Polyatomic Ions: -1 Charge: · Chlorate: CO3-1 · Chlorite: ClO2-1 · Cyanide: CN-1 · Dihydrogen Phosphate: H2PO4-1 · Ethanoate: CH3COO -1 ·...